Your anger is valid, your heartbreak is valid too. Don't feel bad...just "feel" and get the emotions out. He betrayed your trust by using in your home.
I am glad you are going to get counseling. I am glad he remained in rehab. Have your thought about going to any meetings for yourself? Nar-anon, Al-anon and CoDA have been lifesavers for many of us here.
You need to heal and regain your balance just as much as he does. You have been through traumatic times and it will take time for you to find peace again.
Keep moving forward and taking care of yourself. No guilt, it's perfectly okay to take care of yourself.
Hugs